RELAXATIONAL DYNAMICS IN MOLECULAR GLASS FORMERS

The microscopic dynamics of two archetypal molecular glassy materials is discussed on the basis of comparisons between experimental and comp uter simulation results. Such an approach enables one to establish the microscopic origin of the high-frequency relaxations and the survival in the liquid phase of collective excitations characteristic of the g lass. Finally the existence of a length scale involving the coupled mo tions of groups of particles is inferred from the analysis of several experimental and simulated quantities.